Editing the Camouflage Mask on a standard-def. model (i.e Bct. 25t)

Yo! First things first, well, is it even possible? A friend of mine is trying to make a skin for the Batchat 25t and wants to make camouflage applied to the tank invisible, but can't seem to find out how (and I have basically no experience with that stuff and couldn't seem to find anything on my mediocre search for information; assuming it doesn't just work in a similar way to the guide Milky recently made).

Or not. Apparently my friend tested it with his Batchat 25t, but nothing changed. I tested it myself just earlier with the TOG II And also saw no change with the camouflage on the tank, see screenshots below (the before and after of the CM_hd file; I also changed the regular CM File In the same way, just didn't see the need to take another two screenshots of it );

Before

After

I personally believe I might've just messed up on one of the instructions, but I'm pretty sure I nailed it.